Heat exchanger

ABSTRACT

Disclosed herein is a heat exchanger for altering the temperature of water from a fluid circulation line of a recreational body of water. The heat exchanger includes a helical tube-in-tube assembly adapted for flow therethrough of a plurality of fluids for heat transfer therebetween, and the heat exchanger further includes a tank defining a chamber in which said helical tube-in-tube assembly is positioned. In an exemplary embodiment, the chamber is an annular chamber, and the tank includes a cylindrical wall defining an external cavity extending through said tank.

FIELD OF THE INVENTION

The present invention relates generally to a heat exchanger and methods of use thereof. In particular, exemplary embodiments of the invention relate to a heat exchanger for use along a fluid circulation path of a recreational body of water.

BACKGROUND OF THE INVENTION

Tube-in-tube assemblies for use in a heat exchanger are known in the art. An inner tube can be provided for the flow of refrigerant and an outer tube enclosing the inner tube can be provided for the flow therebetween of water. For example, U.S. Patent Publication No. 2003/0209345 discloses a tube-in-tube heat exchanger having a titanium tube for refrigerant surrounded by an outer spa hose, where the heat exchanger is helical for placement around a compressor. As another example, U.S. Pat. No. 5,802,864 discloses a refrigerant-to-water heat exchanger having a refrigerant conduit disposed within a water conduit, where a compressor is positioned within the exchanger.

Among other advantages, a tube-in-tube design increases the surface area for which heat is exchanged between the refrigerant and the water. However, it is contemplated that heat exchangers experience inefficiencies by virtue of the outer water conduit being adjacent to the atmosphere. What is needed in the art is a heat exchanger that overcomes the disadvantages and shortcomings of the prior art.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages and shortcomings of the prior art discussed above by providing a heat exchanger that includes a tank defining a chamber therein for receiving a helical tube-in-tube assembly and/or an external cavity for receiving a compressor.

In the exemplary embodiment, the helical tube-in-tube assembly includes a water hose and a refrigerant tube at least partially extending through the water hose, where the refrigerant tube and the water hose define a primary water passage therebetween. Refrigerant flows through the refrigerant hose and water flows through the primary water passage for the exchange of heat with the refrigerant. It is contemplated that the helical tube-in-tube assembly can optionally be provided with centering means for centering the refrigerant tube within the water hose. In the exemplary embodiment, the heat exchanger includes a diverter positioned within the chamber to direct a primary inflow of water into the primary water passage. The diverter forms a loose seal with the tank to allow a leakage flow of water into the chamber external to the diverter. The tank defines a convergence area where the primary inflow of water and the leakage flow of water converge for flow out of the tank. Heat escaping from water flowing through the primary water passage is transferred to the leakage flow (and/or vice versa, as the case may be).

In an exemplary embodiment of the present invention, the heat exchanger includes at least one wall, such as a cylindrical wall, for defining the external cavity through the tank. The compressor can be positioned within the external cavity so as to be in fluid communication with the helical tube-in-tube assembly. A base and a cover can be provided to cooperate with the inner wall to at least partially enclose the compressor, thereby inhibiting the escape of sound from the external cavity.

In the exemplary embodiment of the present invention, the heat exchanger is provided with a sealing assembly that is releasably secured to the tank so as to permit refrigerant flow between the refrigerant tube and a tube external of the tank, while inhibiting water flow out of the tank at the sealing assembly. The external tube can be in fluid communication with the compressor (and/or other components suitable for the heat cycle). The sealing assembly preferably includes a compression nut having an annular wall opposite the tank and an internally-threaded wall extending from the annular wall toward the tank and in engagement with external threads thereof. The sealing assembly further includes (1) a cap positioned within the compression nut that abuts against the annular wall, (2) a piston positioned adjacent the tank, and (3) a grommet positioned between the cap and the piston. The compression nut, the cap, the grommet, and the piston define a continuous cylindrical opening through which the refrigerant tube extends. The grommet is compressed between the piston and the cap, thereby being deformed radially outward to form a seal with the refrigerant tube.

The heat exchanger includes a plurality of legs, such as a first leg having a first elevation and a second leg having a second elevation greater than the first elevation. The legs are releasably securable to the tank. The tank includes a first post and a second post, and the first leg has a first depression adapted to securingly receive the first post, while the second leg has a second depression adapted to securingly receive the second post. In this regard, the second depression is shaped to inhibit insertion of the first post therein and the first depression is shaped to inhibit insertion of the second post therein.

Additional features, functions and benefits of the disclosed heat exchanger and related systems will be apparent from the detailed description which follows, particularly when read in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference is made to the following detailed description of an exemplary embodiment considered in conjunction with the accompanying drawings, in which:

FIG. 1 is a top plan view of a heating unit that includes a heat exchanger constructed in accordance with an exemplary embodiment of the present invention, the heating unit being shown to include a cabinet with a cover thereof having been removed, the heat exchanger positioned within the cabinet and forming an external cavity, and a compressor positioned within the external cavity;

FIG. 2 is a perspective view of the heat exchanger of FIG. 1;

FIG. 3 is a perspective view of the heat exchanger of FIGS. 1 and 2, the heat exchanger being shown to include a tank having an upper tank portion, a lower tank portion and a plurality of seals therebetween, a tube-in-tube assembly that is positioned within the tank and that has a refrigerant tube positioned within a water hose, a plurality of sealing assemblies each at an end of the refrigerant tube, a water inlet nipple and diverter box positioned adjacent a first end of the water hose, a water outlet nipple positioned adjacent a second end of the water hose, a temperature sensor in fluid communication with the water inlet nipple, a plurality of legs, and a plurality of extension tubes for connecting the refrigerant tube to the compressor of FIG. 1;

FIG. 4 is a cross-sectional view of the heat exchanger of FIGS. 1-3, the cross-section having been taken along section line 4-4 of FIG. 2;

FIG. 5 is a front elevational view of the lower tank portion of FIG. 3;

FIG. 6 is a sectional view of the lower tank portion of FIG. 5, the section having been taken along section line 6-6 of FIG. 5;

FIG. 7 is a top plan view of the lower tank portion of FIG. 3;

FIG. 8 is a first sectional view of the lower tank portion of FIG. 3, the first section having been taken along section line 8-8 of FIG. 7;

FIG. 9 is a second sectional view of the lower tank portion of FIG. 3, the section having been taken along section line 9-9 of FIG. 7;

FIG. 10 is a bottom plan view of the lower tank portion of FIG. 3, the lower tank portion being shown to have a plurality of shaped posts formed integrally therewith;

FIG. 11 is a perspective view of the diverter box of FIG. 3;

FIG. 12 is a front elevational view of the upper tank portion of FIG. 3;

FIG. 13 is a sectional view of the upper tank portion of FIG. 12, the section having been taken along section line 13-13 of FIG. 12;

FIG. 14 is a top plan view of the upper tank portion of FIG. 12;

FIG. 15 is a first sectional view of the upper tank portion of FIG. 12, the first section having been taken along section line 15-15 of FIG. 14;

FIG. 16 is a second sectional view of the upper tank portion of FIG. 12, the section having been taken along section line 16-16 of FIG. 14;

FIG. 17 is a front elevational view of the outlet nipple of FIG. 3;

FIG. 18 is a cross-sectional view of the outlet nipple of FIGS. 3 and 17, the cross-section having been taken along section line 18-18 of FIG. 3;

FIG. 19 is a front elevational view of the inlet nipple of FIG. 3;

FIG. 20 is a cross-sectional view of the inlet nipple of FIGS. 3 and 19, the cross-section having been taken along section line 20-20 of FIG. 3;

FIG. 21 is an enlarged view of an end of the refrigerant tube of FIG. 3;

FIG. 22 is an exploded front perspective view of one of the sealing assemblies of FIG. 3, the sealing assembly being shown to include an O-ring, a piston, a grommet, a cap, and a compression nut;

FIG. 23 is an exploded rear perspective view of the sealing assembly of FIG. 22;

FIG. 24 is a cross-sectional view of the sealing assembly of FIGS. 22 and 23, the cross-section having been taken along section line 24-24 of FIG. 23;

FIG. 25 is a cross-sectional view of the sealing assembly of FIG. 24 in combination with outlet threads of the upper tank portion of FIG. 12, the grommet of the sealing assembly being compressed between the piston and the cap by the compression nut;

FIG. 26 is an elevational view of a tall one and a short one of the legs of FIG. 3;

FIG. 27 is a perspective view of the tall leg and the short leg of FIG. 26;

FIG. 28 is an enlarged view of a first one of the plurality of shaped posts shown in FIG. 10;

FIG. 29 is an enlarged view of a second one of the plurality of shaped posts shown in FIG. 10;

FIG. 30 is perspective view of the tube-in-tube assembly of FIG. 3 with the water hose being shown to be transparent for illustrative purposes only, the tube-in-tube assembly including a plurality of hangers for centering the refrigerant tube within the water hose; and

FIG. 31 is a cross-sectional view of the tube-in-tube assembly of FIG. 30, the cross-section having been taken along section line 31-31 of FIG. 30.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

Referring to FIG. 1, a top plan view of a heating unit 10 is shown. The heating unit 10 is in fluid communication with a fluid circulation line (not shown) of a recreational body of water, such as a swimming pool, spa, etc. A pump (not shown) is typically provided along the fluid circulation line for pumping water therethrough, and filter(s) and/or strainer(s) (not shown) are provided along the fluid circulation line for filtering/straining water upstream from the heating unit 10. The heating unit 10 includes an enclosed cabinet 12, which has a base plate 14, a cylindrical cabinet side wall 16, and a cover 18 that is shown in FIG. 1 to have been removed to reveal a cabinet space (not designated) defined within the cabinet 12. A heat exchanger 20 constructed in accordance with an exemplary embodiment of the present invention is shown to be positioned within the space of the cabinet 12 and fastened to the base plate 14.

Referring to FIGS. 1 and 2, the heat exchanger 20 includes a water outlet nipple 22 and a water inlet nipple 24 that each extend through the cabinet side wall 16 to facilitate attachment thereof to the fluid circulation line without removal of the cover 18 being required. The heat exchanger 20 defines an external cavity 26 in which a compressor 28 is shown to be positioned. A plurality of external tube extensions 30 a, 30 b can be provided between the heat exchanger 20 and the compressor 28 for fluid communication therebetween of refrigerant. Additional components of the heating unit 10 for use in the heat cycle can be in communication with the extensions 30 a, 30 b. As discussed with further detail below, the heat exchanger 20 is adapted to have water flow therethrough from the water inlet nipple 24 to the water outlet nipple 22, during which time heat is transferred, such as from the refrigerant to the water. Also discussed below, the position of the compressor 28 within the external cavity 26 reduces the amount of sound from the compressor 28 that is perceptible by a user of the heat exchanger 20, e.g., the amplitude of compressor noise escaping the heat exchanger 20 is minimized.

Referring to FIGS. 2-4, the heat exchanger 20 includes a tank 32 that defines an annular chamber 34 extending about a central axis A_(T) and that further defines the external cavity 26 along the central axis A_(T). The tank 32 includes an upper tank portion 36, a lower tank portion 38 electromagnetically welded thereto, and a plurality of ribbon seals 40 a, 40 b positioned between the upper tank portion 36 and the lower tank portion 38. A plurality of legs 42 a-c are provided for supporting the tank 32. In those embodiments of the invention in which the heat exchanger 20 is provided with the heating unit 10, the legs 42 a-c can be used in combination with screws 44 a-c for removably securing the tank 32 to the base plate 14 of the heating unit 10.

The heat exchanger 20 includes a tube-in-tube assembly 46 that has a spiral shape and that is positioned within the annular chamber 34 of the tank 32 to extend helically about the axis A_(T). The external cavity 26 extends in an axial direction and through the tube-in-tube-assembly 46. The tube-in-tube assembly 46 includes a water hose 48 and a refrigerant tube 50 extending therethrough. The refrigerant tube 50 is preferably formed from titanium and is adapted for having refrigerant flow therethrough. The water hose 48 terminates at ends thereof that are referenced herein as water hose ends 52 a, 52 b. The refrigerant tube 50 extends out past the water hose ends 52 a, 52 b and terminates outside the water hose 48 at ends that are referenced herein as refrigerant tube ends 54 a, 54 b. Lock rings 56 a, 56 b secure the refrigerant tube ends 54 a, 54 b, respectively, to the external tube extensions 30 a, 30 b, respectively, for fluid communication of the refrigerant between the refrigerant tube 50 and the compressor 28.

A primary water passage 58 is defined by an annular space formed between the water hose 48 and the refrigerant tube 50. The primary water passage 58 is in fluid communication with the water outlet nipple 22 and the water inlet nipple 24, which are provided with O-rings referenced herein as ring seals 60 a, 60 b. The water inlet nipple 24 and the water outlet nipple 22 are adapted for fluid communication with the fluid circulation line of the recreational body of water, e.g., swimming pool, spa, etc., to receive water to be heated in the primary water passage 58 by the refrigerant tube 50 and to provide water that has been heated by the refrigerant tube 50, respectively. The water inlet nipple 24 is provided with a temperature sensor 62, a mounting strap 64 therefor, a drain plug 66, and a drain plug seal 68. Also, a water diverter 70 is positioned within the annular chamber 34 adjacent the water inlet nipple 24. The water diverter 70 is sized and shaped to direct principal water flow to the primary water passage 58 (and is loosely fitted against the tank 32 to facilitate a secondary “leakage flow” of water outside of the primary water passage 58 for upward flow through the annular chamber 34). It is preferable that the direction of principal water flow through the primary water passage 58 be counter to the direction of refrigerant flow through the refrigerant tube 50. A plurality of sealing assemblies 72 a, 72 b are provided for sealing the refrigerant tube ends 54 a, 54 b, such that water is inhibited from escaping the tank 32 at the sealing assemblies 72 a, 72 b. Each one of the sealing assemblies 72 a, 72 b includes an O-ring 74, a piston 76, a grommet 78, a cap 80, and a compression nut 82, which shall each be discussed in further detail below with principal reference to FIGS. 22-25.

Referring to FIGS. 5-10 and 12-16, the tank 32 includes a lower tank portion 38 and an upper tank portion 36 electromagnetically welded therewith. As shall be further discussed below with further detail, both the lower tank portion 38 and the upper tank portion 36 include an inner wall portion (designated below as portions 84, 122) that cooperate to define an inner wall of the tank 32 through which the external cavity 26 extends. Also, both the lower tank portion 38 and the upper tank portion 36 include an outer wall portion (designated below as portions 86, 124) that cooperate to define an outer wall of the tank 32.

Referring to FIGS. 5-10, the lower tank portion 38 of the tank 32 shall now be discussed with further detail. The lower tank portion 38 includes at least one inner wall portion 84 extending about the axis A_(T) to define a portion of the external cavity 26 and at least one outer wall portion 86 extending about the axis A_(T), such that the inner wall portion 84 and the outer wall portion 86 define therebetween a portion of the annular chamber 34. The lower tank portion 38 further includes a bottom wall 88 extending from the inner wall portion 84 to the outer wall portion 86 to at least partially enclose the annular chamber 34.

The inner wall portion 84 of the lower tank portion 38 terminates at an end opposite the bottom wall 88 with a first annular finger set 90 having a first pair of annular fingers that define a first annular space therebetween. Similarly, the outer wall portion 86 of the lower tank portion 38 terminates at an end opposite the bottom wall 88 with a second annular finger set 92 having a second pair of annular fingers that define a second annular space therebetween. The first and second annular finger sets 90, 92 mate with the upper tank portion 36 to securingly align the lower tank portion 38 thereto during electromagnetic welding of the tank portions 36, 38 to one another.

With principal reference to FIG. 8, the outer wall portion 86 has a first elevation E₁ and the inner wall portion 84 has a second elevation E₂ greater than the first elevation E₁. Also, an imaginary geometric plane aligned with the annular finger set 92 has been designated in FIG. 8 as plane H_(O) for the purpose of showing that the distance between the plane H_(O) and the bottom wall 88 is preferably multiform. For example, in the exemplary embodiment of the present invention, there is a first distance H₁ between the plane H_(O) and the bottom wall 88 and a second distance H₂ between the plane H_(O) and the bottom wall 88 that is greater than the first distance H₁. More particularly, the bottom wall 88 is preferably inclined such that the distance from the finger set 92 to the bottom wall 88 increases between from the distance H₁ to the distance H₂.

Continuing with reference to FIGS. 5-10, the lower tank portion 38 includes a drain opening 94, an alignment tab 96, and a plurality of shaped posts 98 a-c. The drain opening 94 extends from the outer wall portion 86 of the lower tank portion 38 and is preferably plugged with a removable drain plug (not shown). The alignment tab 96 is positioned along the outer wall portion 86 of the lower tank portion 38 proximal the finger set 92 for securingly aligning the upper tank portion 36 with the lower tank portion 38 during attachment of the upper tank portion 36 thereto, such as by electromagnetic welding. The shaped posts 98 a-c are provided for engaging the legs 42 a-c and shall be discussed with further detail below in connection with the legs 42 a-c.

The lower tank portion 38 has formed therein a plurality of passages, including a water inlet passage 100 and a refrigerant tube outlet 102. Each of the water inlet passage 100 and the refrigerant tube outlet 102 extend from the outer wall portion 86 proximal the bottom wall 88. The refrigerant tube outlet 102 has external threads 104 for engagement with the seal assembly 72 b. The water inlet passage 100 preferably extends about ninety degrees with respect to the refrigerant tube outlet 102. The water inlet passage 100 has an annular groove 106 formed at an end thereof for receiving the ring seal 60 b and is further discussed below in connection with the water inlet nipple 24.

Referring to FIGS. 3-4, 6, 9, and 11, the annular chamber 34 includes an area proximal the water inlet passage 100 that is referenced herein as a water diversion area 108. The water diversion area 108 is a space defined by the diverter 70 of FIGS. 3, 4, and 11, which, as further discussed below, forms a loose seal with the outer wall portion 86 to channel a principal flow of water from the water inlet passage 100 into the primary water passage 58 (while allowing a desired amount of leakage flow of water into that area of the annular chamber 34 outside the water diversion area 108).

As shown in FIG. 11, the exemplary diverter 70 is configured to sit atop the bottom wall 88 of the lower tank portion 38 within the annular chamber 34. The diverter 70 includes a first retaining wall 110 having an opening 112 formed therethrough. The water hose 48, which is preferably corrugated, extends through the opening 112, such that the water hose end 52 a is securingly retained by the first retaining wall 110. The refrigerant tube 50 extends through the water diversion area 108, and the diverter 70 includes a second retaining wall 114 defining an opening 116 through which the refrigerant tube end 54 b extends. The diverter 70 further includes a plurality of walls 118 a-c that extend between the first and second retaining walls 110, 114 and cooperate with the first and second retaining walls 110, 114 and the outer wall portion 86 to at least partially enclose the diversion area 108. It is desirable for the walls 110, 114, 118 a, 118 b, and 118 c to form a loose seal with the bottom wall 88 and/or the outer wall portion 86, such that water flowing into the diversion area 70 from the water inlet passage 100 is principally channeled into the primary water passage 58 at the water hose end 52 a. At the same time, the loose seal allows a secondary, leakage flow of water flow into that portion of the annular chamber 34 outside of the diverter 70, such that the annular chamber 34 fills with water to the top of the upper tank portion 36 of the tank 32. As discussed further below, it is contemplated the leakage flow from the diverter 70 into the annular chamber 34 generally can be utilized to bypass the primary water passage 58 when the pressure and/or water flow rate is undesirably high. Also, the water outside the water hose 48 in the annular chamber 34 absorbs that heat escaping through the wall of the hose 48 from that water in the primary water passage 58. The diverter 70 includes a hook 120 for securing the diverter 70 at an eyehole (not shown) formed in the lower tank portion 38 to inhibit the diverter 70 from floating to the top of the annular chamber 34 and/or other motion causes by the water within the annular chamber 34.

Referring to FIGS. 12-16, the upper tank portion 36 shall now be discussed with further detail. The upper tank portion 36 includes at least one inner wall portion 122 extending about the axis A_(T) to define a portion of the external cavity 26 extending along the axis A_(T). The upper tank portion 36 further includes at least one outer wall portion 124 extending about the axis A_(T), such that the inner wall portion 122 and the outer wall portion 124 define therebetween a portion of the annular chamber 34 therebetween. Also, the upper tank portion 36 has a top wall 126 that is opposite the bottom wall 88 of the lower tank portion 38 and that extends from the inner wall portion 122 of the upper tank portion 36 to the outer wall portion 124 of the upper tank portion 36 to at least partially enclose the annular chamber 34. As shown, each one of the inner and outer wall portions 122, 124 of the upper tank portion 36 (and the inner and outer wall portions 84, 86 of the lower tank portion 38) can have a cylindrical shape.

Referring to FIGS. 3 and 12-16, the upper tank portion 36 is securingly aligned with the lower tank portion 38. More particularly, the inner wall portion 122 of the upper tank portion 36 terminates at an end opposite the top wall 126 of the upper tank portion 36 with a first annular flange 128. The first annular flange 128 of the upper tank portion 36 mates with the first annular finger set 90 of the lower tank portion 38, and the ribbon seal 40 b is positioned between the first annular flange 128 and the first annular finger set 90. Also, the outer wall portion 124 of the upper tank portion 36 terminates at an end opposite the top wall 126 of the upper tank portion 36 with a second annular flange 130. The second annular flange 130 of the upper tank portion 36 mates with the second annular finger set 92 of the lower tank portion 38, and the ribbon seal 40 a is positioned between the second annular flange 130 and the second annular finger set 92. The upper tank portion 36 is provided with an alignment tab 132 that engages the alignment tab 96 of the lower tank portion 38 to secure the upper tank portion 36 thereto.

The upper tank portion 36 has formed therein a plurality of passages, including a water outlet passage 134 and a refrigerant tube inlet 136. Each of the water outlet passage 134 and the refrigerant tube inlet 136 extend from the outer wall portion 124 of the upper tank portion 36 and proximal the top wall 126 thereof. The refrigerant tube inlet 136 has external threads 138 for engagement with the seal assembly 72 a as further discussed below with reference to FIG. 25. The water outlet passage 134 has an annular groove 140 formed at an end thereof for receiving the ring seal 60 a and is further discussed below in connection with the water outlet nipple 22. The alignment tabs 96, 132 cooperate with one another to securingly align the upper and lower tank portions 36, 38, such that the water outlet passage 134 of the upper tank portion 36 extends parallel with respect to the water inlet passage 100 of the lower tank portion 38.

Referring to FIGS. 3, 13, and 15, the annular chamber 34 includes an area proximal the water outlet passage 134 that is referenced herein as a water convergence area 142. As best shown in FIG. 3, an open area, e.g., the water convergence area 142, is provided where the refrigerant tube end 54 a extends past the water hose end 52 b. Water from the primary water passage 58, as well as leakage flow rising through the annular chamber 36 from the loose seal formed at the diverter 70, converge at and/or proximal the water convergence area 142 for flow out through the water outlet passage 134.

Referring to FIGS. 3 and 17-20, the water outlet nipple 22 and the water inlet nipple 24 shall now be discussed with further detail. As shown in FIGS. 3 and 17-18, the water outlet nipple 22 includes a generally cylindrical wall 144 a with a tank attachment end 146 a and a line attachment end 148 a opposite the tank attachment end 146 a. The tank attachment end 146 a includes an annular flange 150 a that mates with the annular groove 140 of the water outlet passage 134 of the upper tank portion 36. As shown in FIG. 3, the ring seal 60 b is positioned between the annular groove 140 and the annular flange 150 a. The line attachment end 148 a has an annular groove 152 a formed therein and external threads 154 a for coupling the water outlet nipple 22 to that portion of the fluid circulation line (not shown) of the recreational body of water that is downstream of the heat exchanger 20. The line attachment end 148 a can be provided with any additional and/or alternative structure suitable for coupling the water outlet nipple 22 to the fluid circulation line.

Referring to FIGS. 3 and 19-20, the water inlet nipple 24 is similar in some respect to the water outlet nipple 22. For the example, the water outlet nipple 24 includes a generally cylindrical wall 144 b with a tank attachment end 146 b and a line attachment end 148 b opposite thereto. The tank attachment end 146 b includes an annular flange 150 b that mates with the annular groove 106 of the water inlet passage 100 of the lower tank portion 38, and the ring seal 60 a is positioned between the annular groove 106 and the annular flange 150 b. The line attachment end 148 b has an annular groove 152 b formed therein and external threads 154 b for coupling the water inlet nipple 24 to that portion of the fluid circulation line (not shown) of the recreational body of water that is upstream of the heat exchanger 20. The line attachment end 148 b can be provided with any additional and/or alternative structure suitable for coupling the water inlet nipple 24 to the fluid circulation line.

Continuing with reference to FIGS. 3, 19, and 20, the water inlet nipple 24 can advantageously be provided with other features. For example, the exemplary water inlet nipple 24 has a first passage 156 formed therein for receiving the temperature sensor 62, such that the first passage 156 is in fluid communication with water flowing through the cylindrical wall 144 b for sensing the temperature of such water. A plurality of annular bosses 158 are formed on the outer surface of the cylindrical wall 144 b for securingly aligning the mounting strap 64 that is used to removably secure the temperature sensor 62 to the water inlet nipple 24. As another example, the exemplary water inlet nipple 24 has a second passage 160 formed therein for receiving the drain plug 66, such that the second passage 160 is in fluid communication with water flowing through the cylindrical wall 144 b for drainage thereof. In this regard, a depression 162 having a radius greater than that of the second passage 160 is provided in alignment therewith for receiving the drain plug seal 68.

Referring to FIGS. 3 and 21-25, the seal assemblies 72 a, 72 b shall now be discussed with further detail. As shown in FIGS. 3 and 21, the refrigerant tube 50 includes the refrigerant tube ends 54 a, 54 b and a refrigerant tube body 164 extending therebetween. The refrigerant tube body 164 preferably has a spiraled outer surface for inducing turbulent flow of water in the primary water passage 58, thereby facilitating more efficient heat transfer. However, the refrigerant tube ends 54 a, 54 b preferably have substantially cylindrical outer surfaces to be received by the seal assemblies 72 a, 72 b, respectively. Further discussion of the seal assemblies 72 a, 72 b (and the refrigerant tube ends 54 a, 54 b) shall now be made with respect to the seal assembly 72 a (and the refrigerant tube end 54 a), and it shall be understood that such discussion is similarly applicable with respect to seal assembly 72 b (and the refrigerant tube end 54 b).

Referring to FIGS. 21-25, the seal assembly 72 a includes the O-ring 74, the piston 76, the grommet 78, the cap 80, and the compression nut 82. The seal assembly 72 a further includes a continuous cylindrical opening 166 extending through the O-ring 74, the piston 76, the grommet 78, the cap 80, and the compression nut 82 along a central axis, referenced herein as axis A_(SA). The continuous cylindrical opening 166 has a radius just greater than that of the refrigerant tube end 54 a, such that the refrigerant tube end 54 a extends through and out of the continuous opening 166 (see FIG. 25). The seal assembly 72 a is operable between a relaxed state and a compressed state, in which the cap 80 cooperates with the piston 76 to compress the grommet 78 when the compression nut 82 has engaged the external threads 138 of the refrigerant tube inlet 136.

The compression nut 82 includes an open end 168 and a cylindrical, internally-threaded wall 170 for respectively receiving the refrigerant tube inlet 136 into an internal chamber 172 of the nut 82 and mating with the external threads 138 thereof. The compression nut 82 further includes a flat annular wall 174 opposite the open end 168 extending radially inward from the internally-threaded wall 170 of the compression nut 82. An opening 176 extends through the flat annular wall 174 along the axis A_(SA). In some embodiments of the present invention, the O-ring 74, the piston 76, the grommet 78, and the cap 80 are each received into the internal chamber 172 of the nut 82.

The piston 76 is positioned proximal the refrigerant tube inlet 136 (or, in the case of the seal assembly 72 b, the refrigerant tube outlet 102) and is received by the compression nut 82. The piston 76 includes an annular piston wall 178 that defines that portion of the continuous opening 166 extending through the piston 76 and further includes a tapered section 180 that tapers in a direction toward the refrigerant tube inlet 136 (or, in the case of the seal assembly 72 b, the refrigerant tube outlet 102). The annular piston wall 178 has a first portion 182 with a first inner radius that is just greater than that the refrigerant tube ends 54 a, 54 b and a second portion 184 with a second inner radius that is greater than the first inner radius, such that the second portion 184 is widened to receive the grommet 78 for seating thereof at the tapered section 180. An annular rim 186 extends radially outward from the tapered section 180 and terminates at a position adjacent the internally-threaded wall 170.

The piston 76 includes an annularly grooved flange 188 that extends from the rim 186 concentrically with respect to the first portion 182 of the annular piston wall 178. The annularly grooved flange 188 receives in a groove 190 thereof the O-ring 74, such that the O-ring 74 is spaced apart from the internally-threaded wall 170 of the compression nut 82. The grooved flange 188 and the first portion 182 of the annular piston wall 178 define a first annular space 192 therebetween, which is further discussed below.

The piston 76 further includes a lipped flange 194 having a flange 196 that extends from the rim 186 substantially concentrically with respect to the second portion 184 of the annular piston wall 178 and that, together with the second portion 184 of the piston wall 178, defines a second annular space 198.

It is desirable for the walls of the piston 76 to be of substantially equal thickness to minimize warping, including, for example, the flange 196, the second portion 184 of the piston wall 178, the grooved flange 188, and the first portion 182 of the piston wall 178. In this regard, the first and second annular spaces 192, 198 are sized and dimensioned for such purposes.

The flange 196 terminates at an end opposite the rim 186 with a piston lip 200 that extends radially toward the internally-threaded wall 170 of the compression nut 82, such that the lipped flange 194 and the annularly-grooved flange 188 of the piston 76 cooperate with the internally-threaded wall 170 of the compression nut 82 to define an annular space, herein referenced as a receiving area 202, for receiving the external threads 138 of the refrigerant tube inlet 136 (or, in the case of seal assembly 72 b, the external threads 104 of the refrigerant tube outlet 102).

Continuing with reference to FIGS. 21-25, the grommet 78 is formed of a resiliently deformable material, such as rubber. The grommet 78 includes a substantially cylindrical grommet body 204 defining therein a portion of the continuous opening 166 having a radius just greater than each of the refrigerant tube ends 54 a, 54 b. The grommet 78 further includes a beveled portion 206 extending from the body 204 and also defining therein a portion of the continuous opening 166 having a radius just greater than each of the refrigerant tube ends 54 a, 54 b. The grommet 78 is received by the piston 76, such that the beveled portion 206 of the grommet 78 is positioned within a space (not designated) defined by the tapered section 180 of the annular piston wall 178, and such that the grommet body 204 is positioned within a space (not designated) defined by the second portion 184 of the annular piston wall 178.

The cap 80 is received by the piston 76 and is positioned between the grommet 78 and the compression nut 82. The cap 80 includes an annular wall, which is referenced herein as a cap body 208, and which defines therein a portion of the continuous opening 166 of the seal assembly 72. The cap body 208 is received within the second portion 184 of the annular piston wall 178 in abutment with the grommet 78. The cap 80 further includes a lip, which is referenced herein as a cap lip 210, and which extends radially from the cap body 208 at an end thereof opposite the grommet 78 and proximal the flat annular wall 174 of the compression nut 82. The radius of the cap lip 210 is greater than the radius of the opening 176 that extends through the flat annular wall 174, such that the cap lip 210 abuts the flat annular wall 174.

As indicated above, each one of the seal assemblies 72 a, 72 b has a relaxed state when disengaged from a corresponding one of the external threads 104, 138 and a compressed state when engaged with the corresponding one of the external threads 104, 138. In this regard, with continuing discussion of the seal assemblies 72 a, 72 b by way of exemplary reference to the seal assembly 72 a, an embodiment of the seal assembly 72 a having the relaxed state is shown in FIG. 24 and an embodiment of the seal assembly 72 a having the compressed state is shown in FIG. 25.

Referring to FIG. 24, it is shown that when the seal assembly 72 a is in the relaxed state (e.g., when it is disengaged from the external threads 138), the grommet 78 maintains its natural shape described above. Moreover, the cap 80 is sized, shaped, and dimensioned, such that the cap lip 210 defines an open channel 212 with the piston lip 200.

Referring to FIG. 25, it is shown that when the seal assembly 72 a is in the compressed state, e.g., when it is engaged from the external threads 138, the refrigerant tube end 54 a extends through the continuous opening 166 and the grommet 78 is compressed to form a tight seal with the refrigerant tube end 54 a, while the compression nut 82 is engages the external threads 138. In having positioned the external threads 138 within the receiving area 202 to engage the internally-threaded wall 170 of the compression nut 82, the external threads 138 force the piston lip 200 to close the channel 212 and into abutment with the cap 210, such that the cap 210 is secured between the piston lip 200 and the flat annular wall 174 of the compression nut 82. The grommet 78 is compressed between the piston 76 and the cap 80, thereby being deformed radially outward to form a seal with the refrigerant tube end 54 a.

Further sealing is provided by the O-ring 74, such that when the external threads 138 are positioned within the receiving area 202, the O-ring 74 compresses forming a tight seal. Refrigerant can flow through the seal assemblies 72 a, 72 b, while the flow of water therethrough is inhibited.

Referring to FIGS. 3, 8 and 26-27, the legs 42 a-c shall be discussed with further detail. Because leg 42 a is similar to leg 42 b, it shall be understood that the discussions and drawings of leg 42 a are similarly applicable with respect to the leg 42 b. Each one of the legs 42 a-c is formed of a unitary structure that includes a base 214, a fastening tab 216, and a hole 218 that extends through the fastening tab 216 for receiving a corresponding one of the screws 44 a-c. In this regard, the legs 42 a-42 c can be secured to the base plate 14 of heating unit 10.

The base 214 of the leg 42 c has a first leg elevation E_(L1), and each base 214 of the legs 42 a, 42 b has a second leg elevation E_(L2) that is greater than the first leg elevation E_(L1). In this regard, the legs 42 a-42 c can support the tank 32 despite the bottom wall 88 of the lower tank portion 38 being multiform. For example, each one of the legs 42 a-b can be positioned along the bottom wall 88 where the lower tank portion 38 has a first distance H₁, while the leg 42 c can be positioned along the bottom wall 88 where the lower tank portion 38 has a second distance H₂. In such example, that amount by which the second leg elevation E_(L2) is greater than the first leg elevation E_(L1) is substantially equal to that amount by which the second distance H₂ is greater than the first distance H₁ (e.g., E_(L2)−E_(L1)=H₂−H₁).

Referring to FIGS. 10 and 26-29, the leg 42 c has a first shaped depression 220 formed in an end of the corresponding base 214 opposite the fastening tab 216. Each one of the legs 42 a-b has a second shaped depression 222 formed in an end of the corresponding base 214 opposite the fastening tab 216. In this regard, the first shaped depression 220 is adapted to securingly receive the shaped post 98 c, and each one of the second shaped depressions 222 is adapted to securingly receive the shaped posts 98 a, 98 b. More particularly, the male shape of the shaped post 98 c is complementary to the female shape of first shaped depression 220, and the male shape of the shaped posts 98 a-b is complementary to the female shape of the second shaped depression 222. The male shape of the shaped post 98 c is different than the male shape of each of the shaped posts 98 a-b, and the female shape of first shaped depression 220 is different than the female shape of each of the second shaped depressions 222. Such differences inhibit a user from inadvertently securing one of the legs 42 a-c out of position during assembly of the heat exchanger 20.

Referring to FIGS. 1-4, an exemplary use of the heat exchanger 20 shall now be discussed with further detail. To secure the heat exchanger 20 to the heating unit 10, for example, the heat exchanger 20 is secured to the base plate 14 inside the cabinet 12. The compressor 28 is positioned within the external cavity 26 of the heat exchanger 20 and may be secured to the base plate 14. The heat exchanger 20 is provided in fluid communication with the compressor 28 by securing the external tube extensions 30 a, 30 b to the refrigerant tube ends 54 a, 54 b, respectively, as well to the refrigerant inlet and outlet (not shown) of the compressor 28. Additional components suitable for use in the heat cycle may be provided in communication with the extensions 30 a, 30 b.

The cover 18 is secured to the cabinet 12 opposite the base plate 14. In this regard, the heat exchanger 20 and the cover 18, both alone and in combination, reduce the amount of sound emanating from the compressor 28 to a user thereof. For flow of water, the water inlet nipple 24 and the water outlet nipple 22 are respectively secured to the upstream and downstream sides of the fluid circulation line for the recreational body of water.

When activated, there is preferably a counter-flow as between the refrigerant and the water to enhance heat transfer. In this regard, the heat exchanger 20 receives refrigerant proximal the top wall 126 of the heat exchanger 20, such that the refrigerant is received at the refrigerant tube inlet 136, which travels into the refrigerant tube end 54 a, through the refrigerant tube 50 to the refrigerant tube end 54 b, and out of the refrigerant tube outlet 102 proximal the bottom wall 88 of the annular tank 32. Similarly, the heat exchanger 20 receives water proximal the bottom wall 88 of the heat exchanger 20, such that the water is received at the water inlet passage 100 via the water inlet nipple 24, which travels into the diverter 70. A primary water flow flows through the primary water passage 58 to the convergence area 142, a leakage flow flows up through the annular chamber 34 to the convergence area 142, and the water of the leakage flow and the water of the primary flow converge and flow out of the water outlet nipple 22 via the water outlet passage 134.

The tube-in-tube assembly 46 enhances the efficient transfer of heat from refrigerant in the refrigerant tube 50 to water flowing through the primary water passage 58. Moreover, by positioning the tube-in-tube assembly 46 within an annular chamber 34 that allows for an upward leakage flow of water, the transfer of heat is made further efficient, by having heat that might otherwise be lost to the atmosphere from the water hose 48, transferred to the leakage flow for convergence with the primary flow at the convergence area 142. Moreover, heat transfer is further enhanced by virtue of the chamber 34 having an internal negative geometrical shape that is annular, which minimizes the amount of water external the hose 48 that is not in direct surface-to-surface contact with the hose 48. Additional features may be included for enhancing heat transfer. For example, it is contemplated that the water hose 48 can be corrugated and/or the refrigerant tube body 164 can have a spiraled outer surface, either or both for inducing turbulent flow within the primary water passage 58, thereby enhancing heat transfer.

Referring to FIGS. 30-31, it is contemplated that some embodiments of the invention might be provided with a tube-in-tube assembly 46 having centering means for centering the refrigerant tube 50 within the water hose 48. In this regard, the water hose 48 is shown to be transparent in FIGS. 30-31 to facilitate consideration and discussion of such centering means. The centering means is optional, and the tube-in-tube assembly 46 is not defined so as to require inclusion of the centering means.

Such centering means can include, for example, a plurality of hanger sets 224, each one of the hanger sets 224 spaced from each other one of the hanger sets 224 along the length of the tube-in-tube assembly 46. Each one of the hanger sets 224 includes a plurality of rigid, radially-spaced hangers, such as an opposing pair of hangers 226 a, 226 b. Each one of the hangers 226 a, 226 b includes a corresponding one of a plurality of hook portions 228 a, 228 b, a corresponding one of a plurality of arm portions 230 a, 230 b, and a corresponding one of a plurality of arcuate anchor portions 232 a, 232 b. The hook portions 228 a, 228 are secured to the refrigerant tube 50, and each one of the hook portions 228 a, 228 b is radially and evenly displaced from each other one of the hook portions 228 a, 228 b. Each one of the arm portions 230 a, 230 b extends from a corresponding one of the hook portions 228 a, 228 b to a corresponding one of the arcuate anchor portions 232 a, 232 b through a corresponding slit (not shown) formed in the water hose 48. The curvature of the arcuate anchor portions 232 a, 232 b preferably follows the curvature of the water hose 48, and the length of the arm portions 230 a, 230 b is selected such that the anchor portions 232 a, 232 b pull the refrigerant tube 50 with equal force and within the primary water passage 58, such that the refrigerant tube 50 is centered within the water hose 48. Water escaping through the slits from the primary water passage 58 to that area external thereof in the annular chamber 34 joins the upward leakage flow.

Additional and/or alternative centering means are contemplated. For example, it is contemplated that the ribs forming corrugations in the water hose 48 and/or the spiraled outer surface of the refrigerant tube body 164 can be sized and shaped so as to center the refrigerant tube 50 within the water hose 50, while still defining a primary water passage 58 therebetween for flow of water.

It shall be understood that the embodiments of the present invention described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications, including those discussed above, are intended to be included within the scope of the invention as defined in the appended claims. 

1. A heat exchanger for altering the temperature of water from a fluid circulation line of a recreational body of water, comprising: a helical tube-in-tube assembly adapted for flow therethrough of a plurality of fluids for heat transfer therebetween; and a tank defining therein an annular chamber in which said helical tube-in-tube assembly is positioned.
 2. The heat exchanger of claim 1, wherein said tank includes at least one inner wall defining an external cavity extending through said tank.
 3. The heat exchanger of claim 2, wherein said at least one inner wall is a cylindrical wall.
 4. The heat exchanger of claim 2 in combination with a compressor positioned within said external cavity, said compressor being in fluid communication with said helical tube-in-tube assembly for sending thereto and receiving therefrom one of said plurality of fluids.
 5. The combination of claim 4 in further combination with a base and a cover, said base and said cover cooperating with said at least one inner wall to at least partially enclose said compressor, thereby inhibiting the escape of sound from said external cavity.
 6. The combination of claim 4, wherein said one of said plurality of fluids is refrigerant.
 7. The heat exchanger of claim 1, wherein said helical tube-in-tube assembly includes a water hose and a refrigerant tube at least partially extending through said water hose, said refrigerant tube and said water hose defining a primary water passage therebetween adapted for flow of water therethrough.
 8. The heat exchanger of claim 7, wherein said helical tube-in-tube assembly is provided with centering means for centering said refrigerant tube within said water hose.
 9. The heat exchanger of claim 7, further including a sealing assembly releasably secured to said tank so as to permit refrigerant flow between said refrigerant tube and a tube external of said tank and so as to inhibit water flow out of said tank at said sealing assembly.
 10. The heat exchanger of claim 9, wherein said sealing assembly includes: a compression nut having an annular wall opposite said tank and an internally-threaded wall extending from said annular wall to said tank in engagement with external threads thereof; a cap positioned within said compression nut and abutting against said annular wall; a piston positioned adjacent said tank; and a grommet positioned between said cap and said piston; said compression nut, said cap, said grommet, and said piston defining a continuous cylindrical opening through which said refrigerant tube extends.
 11. The heat exchanger of claim 10, wherein said grommet is compressed between said piston and said cap, thereby being deformed radially outward to form a seal with said refrigerant tube.
 12. The heat exchanger of claim 7, further including a diverter positioned within said annular chamber to direct a primary inflow of water into said primary water passage.
 13. The heat exchanger of claim 12, wherein said diverter forms a loose seal with said tank to allow a leakage flow of water into said annular chamber external to said diverter.
 14. The heat exchanger of claim 13, wherein said tank defines a convergence area where said primary inflow of water and said leakage flow of water converge for flow out of said tank.
 15. The heat exchanger of claim 1, further including a first leg having a first elevation and a second leg having a second elevation greater than said first elevation, said first leg and said second leg being releasably securable to said tank.
 16. The heat exchanger of claim 15, wherein said tank includes a first post and a second post, said first leg including a first depression adapted to securingly receive said first post, said second leg including a second depression adapted to securingly receive said second post, wherein said second depression is shaped to inhibit insertion of said first post therein and said first depression is shaped to inhibit insertion of said second post therein.
 17. A heat exchanger for altering the temperature of water flowing through a fluid circulation line of a recreational body of water, comprising: a helical tube-in-tube assembly adapted for flow therethrough of a plurality of fluids for heat transfer therebetween; and a tank in which said helical tube-in-tube assembly is positioned, said tank defining an external cavity extending axially therethrough.
 18. The heat exchanger of claim 17, wherein said at least one inner wall is a cylindrical wall.
 19. The heat exchanger of claim 17 in combination with a compressor positioned within said external cavity, said compressor being in fluid communication with said helical tube-in-tube assembly for sending thereto and receiving therefrom one of said plurality of fluids.
 20. The combination of claim 19 in further combination with a base and a cover, said base and said cover cooperating with said at least one inner wall to at least partially enclose said compressor, thereby inhibiting the escape of sound from said external cavity.
 21. The heat exchanger of claim 17, wherein said helical tube-in-tube assembly includes a water hose and a refrigerant tube at least partially extending through said water hose, said refrigerant tube and said water hose defining a primary water passage therebetween adapted for flow of water therethrough.
 22. The heat exchanger of claim 21, further including a sealing assembly releasably secured to said tank so as to permit refrigerant flow between said refrigerant tube and a tube external of said tank and so as to inhibit water flow out of said tank at said sealing assembly.
 23. The heat exchanger of claim 22, wherein said sealing assembly includes: a compression nut having an annular wall opposite said tank and an internally-threaded wall extending from said annular wall to said tank in engagement with external threads thereof; a cap positioned within said compression nut and abutting against said annular wall; a piston positioned adjacent said tank; and a grommet positioned between said cap and said piston; said compression nut, said cap, said grommet, and said piston defining a continuous cylindrical opening through which said refrigerant tube extends.
 24. The heat exchanger of claim 23, wherein said grommet is compressed between said piston and said cap, thereby being deformed radially outward to form a seal with said refrigerant tube.
 25. The heat exchanger of claim 21, further including a diverter positioned within a chamber defined by said tank to direct a primary inflow of water into said primary water passage.
 26. The heat exchanger of claim 25, wherein said diverter forms a loose seal with said tank to allow a leakage flow of water into said chamber external of said diverter.
 27. The heat exchanger of claim 26, wherein said tank defines a convergence area where said primary inflow of water and said leakage flow of water converge for flow out of said tank.
 28. A heat exchanger for altering the temperature of water from a fluid circulation line of a recreational body of water, comprising: a helical tube-in-tube assembly adapted for flow therethrough of a plurality of fluids for heat transfer therebetween, said helical tube-in-tube assembly including a water hose and a refrigerant tube at least partially extending through said water hose, and said refrigerant tube and said water hose defining a primary water passage therebetween adapted for flow of water therethrough; a tank defining therein a chamber in which said helical tube-in-tube assembly is positioned; and a sealing assembly releasably secured to said tank so as to permit refrigerant flow between said refrigerant tube and a tube external of said tank and so as to inhibit water flow out of said tank at said sealing assembly.
 29. The heat exchanger of claim 28, wherein said sealing assembly includes: a compression nut having an annular wall opposite said tank and an internally-threaded wall extending from said annular wall to said tank in engagement with external threads thereof; a cap positioned within said compression nut and abutting against said annular wall; a piston positioned adjacent said tank; and a grommet positioned between said cap and said piston; said compression nut, said cap, said grommet, and said piston defining a continuous cylindrical opening through which said refrigerant tube extends.
 30. The heat exchanger of claim 29, wherein said grommet is compressed between said piston and said cap, thereby being deformed radially outward to form a seal with said refrigerant tube. 